Implement dream overlay motion when entering hub

This adds the x translation to the overlay as the hub is swiped in over
the dream.

Bug: 325102385
Test: atest SystemUiRoboTest:DreamingToGlanceableHubTransitionViewModelTest
Flag: ACONFIG com.android.systemui.communal_hub STAGING
Change-Id: Ifa2afa172afd2c7d645bc3bf82c96cb93deae6d9